using System.Diagnostics;
using System.Text;
using Azaion.Common.DTO;
using MessagePack;
using Microsoft.Extensions.Logging;
using Microsoft.Extensions.Options;
using NetMQ;
using NetMQ.Sockets;

namespace Azaion.Common.Services;

public interface IInferenceClient : IDisposable
{
    event EventHandler<RemoteCommand>? InferenceDataReceived;
    event EventHandler<RemoteCommand>? AIAvailabilityReceived;
    void Send(RemoteCommand create);
    void Stop();
}

public class InferenceClient : IInferenceClient
{
    private readonly ILogger<InferenceClient> _logger;
    public event EventHandler<RemoteCommand>? BytesReceived;
    public event EventHandler<RemoteCommand>? InferenceDataReceived;
    public event EventHandler<RemoteCommand>? AIAvailabilityReceived;

    private readonly DealerSocket _dealer = new();
    private readonly NetMQPoller _poller = new();
    private readonly Guid _clientId = Guid.NewGuid();
    private readonly InferenceClientConfig _inferenceClientConfig;
    private readonly LoaderClientConfig _loaderClientConfig;

    public InferenceClient(ILogger<InferenceClient> logger, IOptions<InferenceClientConfig> inferenceConfig, IOptions<LoaderClientConfig> loaderConfig)
    {
        _logger = logger;
        _inferenceClientConfig = inferenceConfig.Value;
        _loaderClientConfig = loaderConfig.Value;
        Start();
    }

    private void Start()
    {
        try
        {
            using var process = new Process();
            process.StartInfo = new ProcessStartInfo
            {
                FileName = Constants.EXTERNAL_INFERENCE_PATH,
                Arguments = $"-p {_inferenceClientConfig.ZeroMqPort} -lp {_loaderClientConfig.ZeroMqPort} -a {_inferenceClientConfig.ApiUrl}",
                CreateNoWindow = true
            };
            process.Start();
        }
        catch (Exception e)
        {
            _logger.LogError(e, e.Message);
        }

        _dealer.Options.Identity = Encoding.UTF8.GetBytes(_clientId.ToString("N"));
        _dealer.Connect($"tcp://{_inferenceClientConfig.ZeroMqHost}:{_inferenceClientConfig.ZeroMqPort}");

        _dealer.ReceiveReady += (_, e) => ProcessClientCommand(e.Socket);
        _poller.Add(_dealer);
        _ = Task.Run(() => _poller.RunAsync());
    }

    private void ProcessClientCommand(NetMQSocket socket, CancellationToken ct = default)
    {
        while (socket.TryReceiveFrameBytes(TimeSpan.Zero, out var bytes))
        {
            if (bytes?.Length == 0)
                continue;

            var remoteCommand = MessagePackSerializer.Deserialize<RemoteCommand>(bytes, cancellationToken: ct);
            switch (remoteCommand.CommandType)
            {
                case CommandType.DataBytes:
                    BytesReceived?.Invoke(this, remoteCommand);
                    break;
                case CommandType.InferenceData:
                    InferenceDataReceived?.Invoke(this, remoteCommand);
                    break;
                case CommandType.AIAvailabilityResult:
                    AIAvailabilityReceived?.Invoke(this, remoteCommand);
                    break;
            }

        }
    }

    public void Stop() =>
        Send(RemoteCommand.Create(CommandType.StopInference));

    public void Send(RemoteCommand command) =>
        _dealer.SendFrame(MessagePackSerializer.Serialize(command));

    public void Dispose()
    {
        _poller.Stop();
        _poller.Dispose();
        _dealer.SendFrame(MessagePackSerializer.Serialize(new RemoteCommand(CommandType.Exit)));
        _dealer.Disconnect($"tcp://{_inferenceClientConfig.ZeroMqHost}:{_inferenceClientConfig.ZeroMqPort}");
        _dealer.Close();
        _dealer.Dispose();
    }
}